The most interesting figures came in a paper submitted at a conference on renewable energy held in Germany in 2004. In “The Potentials of Renewable Energy” there is a chart that estimates the technical maximum energy possible from various forms of renewable energy. Hydropower, 50 exajoules a year. Biomass energy, 250. Solar, 1,600. Wind, 600. Geothermal, 5,000. The total, some 7,500 exajoules a year, or 17 times current demand.

Sure, there is a certain amount of magic-wand waving to come up with such numbers. And getting from here to there will be quite a feat, and won’t be accomplished in a decade or two. It will require a vast realignment of government priorities and considerable technological advancement. And even the most optimistic of projections don’t hold out promise of renwables accounting for more than 50 or 60 percent of world energy demand by 2050.

But with the right kind of political will, we could make a serious difference. Current estimates of government subsidies for the fossil fuel industry range from $50 billion to $250 billion a year. If that funding was diverted to subsidizing renewable energy, solar and wind and biofuels would fast become cost-competitive with oil — even when priced at lower than the current $60 a barrel.

As study after study points out, small-scale renewable energy installations are increasingly appropriate for deployment in impoverished nations where millions still live far from the electricity grid. Widespread rollout would create jobs, fend off the pressures of peak oil, combat global warming and, best of all, decrease the influence that Big Oil currently exerts on world affairs. It’s pretty easy to conclude: Nothing could be more important.

There’s a story today in an East Bay newspaper, the Contra Costa Times, that profiles a biodiesel pumping operation in my home town of Berkeley, Calif. It’s just one pump in a garage, run by a collective of five women — which is about as Berkeley as you can get. On weekends, says the reporter, there’s usually a short wait for a turn at the pump. That’s a market opportunity, if I ever saw one, and some small reason for hope.

The National Petroleum Council is an advisory committee to the DOE made up mostly of representatives from the U.S. oil and gas industry. And it is currently headed by the recently retired CEO of ExxonMobil, Lee Raymond.

Lee Raymond has long been notorious for his personal skepticism about global warming and climate change, and he is on record as declaring, on numerous occasions, that there is nothing to worry about with respect to world oil supplies.

Could there be a worse person in charge of investigating peak oil for the Department of Energy?

Yesterday, a reader of How the World Works took issue with my downplaying of the catastrophe-around-the-corner theory, and challenged me to address the apocalyptic arguments in an unpublished draft of a paper by Jay Hanson.

Jay Hanson could be called the father of the “billions-are-going-to-die-because-of-peak-oil” meme. He created the Web site Dieoff.org and his name is a regular presence in online discussions of peak oil. So let’s take a look at a critical passage from his essay.

“Every day,” writes Hanson, “people burn the fossil fuel equivalent of all the plant matter that grows on land and in the oceans over the course of a whole year. No so-called ‘renewable’ energy system has the potential to generate more than a tiny fraction of the power now being generated by fossil fuels!

“In 2003, the biologist Jeffrey Dukes calculated that the fossil fuels we burn in one year were made from organic matter ‘containing 44 x 10^18 grams of carbon, which is more than 400 times the net primary productivity of the planet’s current biota.’ In plain English, this means that every year we use four centuries’ worth of plants and animals!

“The inevitable decline of global oil production means that the energy available to global society will inevitably fall too; it means the consumer civilization is now over.”

The clear argument espoused here is that it is impossible to replace the fossil fuel-based energy we currently consume with alternative, renewable sources. But there are a couple of holes in Hanson’s logic.

Let’s start with Dukes’ paper, which has received a great deal of attention since its initial publication, and rightly so. But it has also, Dukes told me this morning, often been “misinterpreted” in the blogosphere.

For one thing, the four centuries’ worth of plant and animal matter that became the coal, gas and oil consumed in 1997 represent an extremely clumsy, not to mention slow, method of converting biomass to energy. Although the debate rages on about just how net energy efficient biofuels such as ethanol or biodiesel are, there is little doubt that current production methods are considerably more efficient than the millions-of-years process by which, say, peat swamps get converted into coal. Dukes’ own paper notes that to replace the fossil fuel energy consumed in 1997 with biofuels would consume 22 percent of the biomass produced on earth in that year.

Now, that’s obviously a big, awful number. Converting 22 percent of the earth’s production of biota into fuel would have catastrophic consequences for biodiversity and food supply. Still, there’s a difference between that number and the idea that we need four centuries’ worth of production to make up for each year of consumption.

But it’s also a number that’s kind of beside the point. As Dukes says, it doesn’t include solar or wind or hydroelectric or geothermal power. Nor does it include attempts to cut back on energy consumption, which will be essential for grappling with the oncoming crisis.

As for the assertion that renewable energy will never generate a fraction of the energy produced by burning fossil fuels, well — as Alex Farrell, an assistant professor at U.C. Berkeley’s Energy and Resources Groups notes, global solar energy input to the earth, in a given year, is 5,000 times as great as the amount of energy humans consume in a year. There’s some room to maneuver there.

It’s not going to be easy, and there may well be depressions and recessions and wars and other calamities to face along the way, but it is also not by definition impossible.

“The urgent thing is to bring all these things online as quickly as possible, and do it in a way that is environmentally sustainable,” says Dukes. “We’ve got a huge challenge. The question is, how are we going to face it? You’ve got to take that attitude, you can’t just say forget it.”

In January, researchers at Yale made a buzz when they noted that, according to their calculations, there wasn’t enough copper left to be mined for everybody in developing nations to enjoy the same standard of living as those in the developed world. It seems that as a country gets richer, per capita use of copper climbs — largely because of copper’s great utility in electronic devices.

But where’s that copper going to come from? Copper has been popular for at least 10,000 years, but more than 95 percent of all copper ever mined and smelted has been extracted since 1900. And as India and China race to catch up with the West, copper supplies are getting tight.

In December, a mining executive presented a conference audience with a bleak appraisal of the current copper inventory squeeze. “Globally, economic copper resources are being depleted with the equivalent production of three world-class copper mines being consumed annually; meanwhile, copper demand is increasing by more than 575,000 tons annually and accelerating.” Furthermore, “only 56 new copper discoveries have been made during the past three decades,” and “21 of the 28 largest copper mines in the world are not amenable to expansion, while many large copper mines will be exhausted between 2010 and 2015.”

Perhaps “bleak” isn’t the best word to describe this, at least from a mining executive point of view. With the global economy booming, commodity prices for scores of raw materials are surging, and mining companies are raking in the bucks. Copper company executives note with glee, for example, that hybrid automobiles use two to three times as much copper as standard vehicles. What if, in ten years, everyone in China and India is driving a hybrid? Copper prices will go through the roof! Hallelujah!

Except, if you look at the very latest statistics from the International Copper Study Group, you see some figures that tell a bit of a different story. Although consumption has outstripped supply for the last three years, drawing down worldwide copper inventories to the brink of exhaustion, last year the gap narrowed considerably, and next year, supply is predicted to outstrip consumption. And contrary to Beatty’s claim that demand is increasing by 575,000 tons annually and accelerating, 2005 recorded about the same total usage as 2004. Global usage actually fell during January-November 2005, compared to a similar period a year earlier.

How is this possible? According to the ICSG, growing demand in Asia was more than offset by a decline in demand in the U.S. and Europe. And that, say analysts, is an example of the price mechanism in action. As copper prices have risen, consumers have started to substitute other materials in its place, or become more efficient in their consumption.

So, peak copper? Maybe not. For years, the low price of copper made looking for substitutes uneconomic, but now that’s changed. The same may end up being true for oil, though there are big differences between oil and copper, insofar as it is a lot easier to substitute, say, plastic pipes for copper pipes in your kitchen plumbing, than it is to come up with cheap replacements for oil.

Then again, it may also be true that there won’t be any cheap fixes to copper’s fantastic usefulness in high-tech electronic goods, so the real squeeze is still yet to come.

How the World Works doesn’t intend to be an investment advisor, and it’s always a bad idea to jump into the market when the price of something has just hit an all time high … but still, going long on copper might not be such a crazy idea. Especially if the Chinese start buying up Priuses.

O.K., folks, now it’s time to get worried. When Exxon tells us to relax, Armageddon is undoubtedly right around the corner. Let’s not forget: For years, Exxon has been the single largest corporate donor to a rogue’s gallery of conservative think tanks that make a living pretending that global warming is no big thing. Is there a corporation on the planet that has less credibility?

How the World Works doesn’t know whether, as Princeton geologist Kenneth Deffeyes maintains, we’ve already passed the point of peak oil: when there is less oil left to be extracted than has already been consumed. And we have a lot of sympathy for the almighty power of the price mechanism. Simple economics suggest that new technologies for extracting more oil from already existing fields and new oil from Canada’s oil sands and the Rockies’ oil shale will eventually become feasible (although Exxon neglects to mention that it will be skyrocketing oil prices that provide the necessary incentives).

But the underlying thrust of Exxon’s message is that we have every right to be complacent, and that isn’t just ridiculous, it’s criminal. Demand for oil is increasing every day, and production is just barely keeping up, right now. It is in the best interest of the planet, the global economy, and every living creature that we devote all available resources to conservation, energy efficiency, and the development of alternative sources of energy and conservation. Exxon, sitting on top of a year where tight oil supplies have led to some of the greatest windfall profits any corporation has ever enjoyed, can’t tell us there isn’t a problem. Exxon is the problem.